main.go

package main

import (
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"path/filepath"
	"strconv"
	"strings"
	"syscall"

	"github.com/go-chi/chi"

	"github.com/go-chi/chi/middleware"
	"github.com/lazhari/url-shortener/api"

	mr "github.com/lazhari/url-shortener/repository/mongodb"
	rr "github.com/lazhari/url-shortener/repository/redis"
	"github.com/lazhari/url-shortener/shortener"
)

func main() {
	repo := chooseRepo()
	service := shortener.NewRedirectService(repo)
	handler := api.NewHandler(service)

	r := chi.NewRouter()
	r.Use(middleware.RequestID)
	r.Use(middleware.RealIP)
	r.Use(middleware.Logger)
	r.Use(middleware.Recoverer)

	r.Get("/{code}", handler.Get)
	r.Post("/", handler.Post)

	clientDir, _ := os.Getwd()
	filesDir := http.Dir(filepath.Join(clientDir, "client/build"))

	FileServer(r, "/", filesDir)

	errs := make(chan error, 2)
	go func() {
		fmt.Println("Listening on port :8000")
		errs <- http.ListenAndServe(httpPort(), r)
	}()

	go func() {
		c := make(chan os.Signal, 1)
		signal.Notify(c, syscall.SIGINT)
		errs <- fmt.Errorf("%s", <-c)
	}()
	fmt.Printf("Terminated %s", <-errs)

}

// repo <- service -> serializer -> http
func httpPort() string {
	port := "8000"
	if os.Getenv("PORT") != "" {
		port = os.Getenv("PORT")
	}
	return fmt.Sprintf(":%s", port)
}

func chooseRepo() shortener.RedirectRepository {
	switch os.Getenv("URL_DB") {
	case "redis":
		redisURL := os.Getenv("REDIS_URL")
		repo, err := rr.NewRedisRepository(redisURL)
		if err != nil {
			log.Fatal(err)
		}
		return repo
	case "mongo":
		mongoURL := os.Getenv("MONGO_URL")
		mongoDB := os.Getenv("MONGO_DB")
		mongoTimeout, _ := strconv.Atoi(os.Getenv("MONGO_TIMEOUT"))
		repo, err := mr.NewMongoRepository(mongoURL, mongoDB, mongoTimeout)
		if err != nil {
			log.Fatal(err)
		}
		return repo
	}
	return nil
}

// FileServer static files from a http.FileSystem.
func FileServer(r chi.Router, path string, root http.FileSystem) {
	if strings.ContainsAny(path, "{}*") {
		panic("FileServer does not permit any URL parameters.")
	}

	if path != "/" && path[len(path)-1] != '/' {
		r.Get(path, http.RedirectHandler(path+"/", 301).ServeHTTP)
		path += "/"
	}
	path += "*"

	r.Get(path, func(w http.ResponseWriter, r *http.Request) {
		rctx := chi.RouteContext(r.Context())
		pathPrefix := strings.TrimSuffix(rctx.RoutePattern(), "/*")
		fs := http.StripPrefix(pathPrefix, http.FileServer(root))
		fs.ServeHTTP(w, r)
	})
}